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Took the time yesterday to do some maintenance that I thought was appropriate, no matter what the official BMW stance is on the subject (3 year fuel filter change interval and “lifetime” transmission fluid . . . Both seem too long to me).

First attached pic is of the car up on the lift as the new fuel filter is beling flushed. Was curious if there was evidence of water trapped by the filter. Good news is no free water found. This could mean a couple things: 1) The truck stop used for >95% of fuel must do a good job of keeping free water from their tanks. 2) The fuel filter doesn’t do diddly for stopping free water. Hope #1 is the reason.

Second picture is a comparison of the old transmission fluid to the new fluid (ZF Lifeguard 6 as recommended by the transmission manufacturer). Was a bit surprised at the color and smell of the old fluid at <30,000 mls. Glad it was decided to do a fluid change this early. Considering not all the fluid gets refreshed with the approach used think a 2-3yr change interval will continue to be used on this vehicle.

Took the time yesterday to do some maintenance that I thought was appropriate, no matter what the official BMW stance is on the subject (3 year fuel filter change interval and “lifetime” transmission fluid . . . Both seem too long to me).

First attached pic is of the car up on the lift as the new fuel filter is beling flushed. Was curious if there was evidence of water trapped by the filter. Good news is no free water found. This could mean a couple things: 1) The truck stop used for >95% of fuel must do a good job of keeping free water from their tanks. 2) The fuel filter doesn’t do diddly for stopping free water. Hope #1 is the reason.

Second picture is a comparison of the old transmission fluid to the new fluid (ZF Lifeguard 6 as recommended by the transmission manufacturer). Was a bit surprised at the color and smell of the old fluid at <30,000 mls. Glad it was decided to do a fluid change this early. Considering not all the fluid gets refreshed with the approach used think a 2-3yr change interval will continue to be used on this vehicle.

Me thinks you need to refill the Evan Williams bottle in the background!

Took the time yesterday to do some maintenance that I thought was appropriate, no matter what the official BMW stance is on the subject (3 year fuel filter change interval and “lifetime” transmission fluid . . . Both seem too long to me).

First attached pic is of the car up on the lift as the new fuel filter is beling flushed. Was curious if there was evidence of water trapped by the filter. Good news is no free water found. This could mean a couple things: 1) The truck stop used for >95% of fuel must do a good job of keeping free water from their tanks. 2) The fuel filter doesn’t do diddly for stopping free water. Hope #1 is the reason.

Second picture is a comparison of the old transmission fluid to the new fluid (ZF Lifeguard 6 as recommended by the transmission manufacturer). Was a bit surprised at the color and smell of the old fluid at <30,000 mls. Glad it was decided to do a fluid change this early. Considering not all the fluid gets refreshed with the approach used think a 2-3yr change interval will continue to be used on this vehicle.

My experience has been the same. Automatic transmissions use a thin layer of fluid between plates to create the friction surface, which as you can imagine, has a lot of heat generated. If the fluid is not synthetic, it breaks down even more easily. I have changed it in as little as 13,000 miles to find it to be seriously discolored. Black and junky after 44,000 miles on a Honda.

The larger fuel filters found in TDI's seemed never to have any water when I drained them, nor did they need changing for at least 30K miles.

PL

__________________

Rose Castorini: I just want you to know no matter what you do, you're gonna die, just like everybody else.
Cosmo Castorini: Thank you, Rose. - Moonstruck

My experience has been the same. Automatic transmissions use a thin layer of fluid between plates to create the friction surface, which as you can imagine, has a lot of heat generated. If the fluid is not synthetic, it breaks down even more easily. I have changed it in as little as 13,000 miles to find it to be seriously discolored. Black and junky after 44,000 miles on a Honda.

The larger fuel filters found in TDI's seemed never to have any water when I drained them, nor did they need changing for at least 30K miles.

PL

You can find UOA's on LG6 taken from AT's with over 70k miles and they came back fine. I've personally spoken to an engineer at ZF who informed me that outside their severe service interval the fluid can easily go 100k miles. The mechtronics is the key to long fluid life and once the fluid is changed the transmission needs to be reset (clear adaptations?) so the mechtronics will adjust to the new fluid characteristics (sp?).

You can find UOA's on LG6 taken from AT's with over 70k miles and they came back fine. I've personally spoken to an engineer at ZF who informed me that outside their severe service interval the fluid can easily go 100k miles. The mechtronics is the key to long fluid life and once the fluid is changed the transmission needs to be reset (clear adaptations?) so the mechtronics will adjust to the new fluid characteristics (sp?).

I finally did the dreaded ATF change on the 6 speed ZF transmission. If you read the fine print in the owner’s manual it says to change the ATF at 48,000 kilometers (30,000 miles)if the car is driven in harsh conditions, i.e. stop and go traffic.

Known Problems With BMW
As these are known to be a sealed transmission it is highly recommended to have these serviced. BMW’s have
had these since 2000 which means the transmission would have done may kms on the same oil. As oil does go
off and add many years of wear and tear floating through the oil it all comes together to start causing issues with
shifting etc. Getting in early with a service will help prolong the transmission so your not hit with a large rebuild
cost.

Service Information
The 6HP26 requires a special oil from ZF there are some oil manufactures that claim there fluid will work
however unless its documented that it will work its recommended to use ZF oil. Now vehicle manufactures claim
that the transmission is a “fill for life” or “Sealed Gearbox” however with research we have done we have found
that ZF claim the Lifeguard 6 fluid is rated to 62,000 miles. See below details
“ZF Lifeguard Fluid, a high-performance lubricant specially engineered by ZF, gives customers a perfectly
matched product. The transmission fluid reduces material wear, vibrations and noise for smoother shifting,
extended maintenance intervals (100,000 km/62,000 miles), and maximum fuel savings.”

Transmission Rebuilders recommend servicing these transmissions every 60,000kms or 36 Months which
every accrues first. It is also recommended on models with a one piece plastic sump to be converted with the
more common steel sump with removable filter. The conversion cost about $70AUD more but then you will be
saving $70 every service after that as you only need a filter and gasket rather than a complete sump.

Many use their D's in a heavy duty fashion I would wager. As they say, buyer beware.

PL

__________________

Rose Castorini: I just want you to know no matter what you do, you're gonna die, just like everybody else.
Cosmo Castorini: Thank you, Rose. - Moonstruck

Per ZF with regards to all passenger AT severe service is 8 yrs or 80k-120k KM where vehicle was operating in " frequent hwy driving in top speed range", "offensive,sporty driving style","frequent trailer operation".

The conversion to miles 48k to 72k.

Something to keep in mind is that these new units are holding up very well under normal maintenance. You just don't hear about failures from used car owners.

Per ZF with regards to all passenger AT severe service is 8 yrs or 80k-120k KM where vehicle was operating in " frequent hwy driving in top speed range", "offensive,sporty driving style","frequent trailer operation".

The conversion to miles 48k to 72k.

Something to keep in mind is that these new units are holding up very well under normal maintenance. You just don't hear about failures from used car owners.

Sent from my MB525 using Bimmer App

So, uh, how would you explain the reality of the original post in this thread - how nice the color of the fluid is in "<30,000 miles"??

48k to 72k sounds reasonable, though, given ZF's advanced design adaptive to the quality of the fluid, and, IMO, how most of us drive.

Reality is different than what a marketing department at ZF or any other manufacturer suggests. There are compromises at every step of automotive manufacturing, and automatic transmissions have been somewhat of a disappointment in reliability if you haven't noticed.

Driving like a European driver, with the kind of care they have historically given (remember how beloved Fiats were in Europe when they were trash in the US) is almost totally different from what I affectionately call the "stoplight grand prix" here in the US. High speed driving and long stretches with a locked up torque converter doesn't translate to frequent high torque shifting and gear changes in stop and go driving. Its just a matter of judgement on how to define heavy duty use.

So as I said, buyer beware. My experience has been to change the fluid at least within 30-60,000 miles on traditional planetary gear type automatics. Even DSG's or "auto-manuals" like the one VW has call for 40,000 mile fluid changes.

PL

__________________

Rose Castorini: I just want you to know no matter what you do, you're gonna die, just like everybody else.
Cosmo Castorini: Thank you, Rose. - Moonstruck

Color means little. Wrench boredom is a sickness which we all suffer from it to some degree. Hell I like to change my oil every 6.5k miles. I know it's probably a waste but I just like doing it.

"Hello, my name is John and I am a wrenchaholic". "Hello John! "

Just trying to keep people informed.

Sent from my MB525 using Bimmer App

This does not in any way negate the argument that under heavy use, changing the fluid at 30-60,000 mile intervals is a good precaution. Color is but one indicator and could mean nothing or it could mean burnt fluid: http://www.agcoauto.com/content/news/p2_articleid/141

Good information includes lack of cynicism and respect for real data. Anecdotal data is useless in this respect, but case studies such as incidents of burnt fluid and transmission failures at lower than "forever" mileage are eye-opening. Until there is solid data, we will need to depend on BMW to provide us with recommendations. Heavy duty use is a point that is a judgement call which your cynical comments seem to ignore. Certainly most of us don't baby our cars and this would not be recommended anyway for the common diesel motor which seems to do better with full load.

I believe its also very reasonable to do UOA on the transmission fluid for these ZF boxes to know when to service them.

Agreed. The internet is full of anecdotal support for 30k mile ATF change which people take as gospel and in the same vein manufacturers recommendations are completely disregarded.

I see it time and time again with this brand. People make the irrational and to be honest contradictory confidence in that BMW knows how to design great vehicles using high performance parts but they know absolutely nothing about maintenance .

An interesting example od this is that years ago a local shop had on their website a picture of a customers sludged up BMW I6 and made a comment about BMW's OCI causing this type of sludge. Well because of this the internet was a flurry of all these owners crapping on BMW OCI. I called BS on them because this Indy shop lifted the pic off the internet and the actual story behind THAT engine was that the owner never changed the oil and/or used regular dino juice which wasn't formulated for the factory OCI. The shop was having difficulty getting a straight answer from the owner.

To this day I see photos from that engine popping up.

I just think people should have relevant information from the horses mouth when possible. The decision in the end us theirs.

On side note I saw an online site suggest the incorrect motor oil for a U.S. spec 335i when that brand specifically states not for use in US models. The vendor didn't give any qualifier to using that brand which they should have.

I recently had a BMW (ZF) auto transmisstion faliure in our 2000 540iT at 140K miles. I also did proactive fluid changes every 50K miles. In this case the forward drum cracked. All the fluid changes in the world would not have prevented this.

After this experience ($5K) not sure where I stand anymore on this topic. I certainly will change the fluid before 100K miles, how much before is the question....

Was just trying to add to the knowledge base . . . Agree that smell and color are not a quantifiable basis for determining the quality or deterioration of a fluid. I still have the tranny fluid in that sealed container, thinking now I'll send it off to get tested so there's some quantifiable data.

Guys, we can work together to increase the BMW diesel experience for all of us. These are great, fun cars with a fantastic performance/economy ratio. Hopefully we can help each other.

Skip Miller had his transmission flushed recently and sent the original fluid to Dyson Analysis to see how well it had held up. Skip's comment when seeing the report was "Results were not pretty." He had 78,000 on his 2003 XKR at the time of service; the report may be reviewed at max performance cars dot com under the topic "ZF 6HP26 Transmission Fluid Analysis and Fluid Change," dated "2008/05/04."

Based on this information Skip now prefers a much shorter service interval of 20K

Skip Miller had his transmission flushed recently and sent the original fluid to Dyson Analysis to see how well it had held up. Skip's comment when seeing the report was "Results were not pretty." He had 78,000 on his 2003 XKR at the time of service; the report may be reviewed at max performance cars dot com under the topic "ZF 6HP26 Transmission Fluid Analysis and Fluid Change," dated "2008/05/04."

Based on this information Skip now prefers a much shorter service interval of 20K

You specifically said there are analyses that show fluid is good at 70k.

So I am confused why you are linking to a UOA that shows a failed fluid???? Lower viscosity than is required; higher insolubles; higher wear metals. Their averages are based on 30k miles...this UOA is 2x that in length but wear is 2x, 3x, 5x more.... what are you seeing that says 70k is fine

???

A

PS I am a bit of a fanatic on ATF- if there is data supporting BMWs position, then lets see it...but I refuse to allow causal assertions go unchallenged.

You specifically said there are analyses that show fluid is good at 70k.

So I am confused why you are linking to a UOA that shows a failed fluid???? Lower viscosity than is required; higher insolubles; higher wear metals. Their averages are based on 30k miles...this UOA is 2x that in length but wear is 2x, 3x, 5x more.... what are you seeing that says 70k is fine

???

A

PS I am a bit of a fanatic on ATF- if there is data supporting BMWs position, then lets see it...but I refuse to allow causal assertions go unchallenged.

Look @ links again. There are 2 links @ same mileage(70k). One good one bad.

One thing to keep in mind with UOA's. I have yet to read where BS or any other company state that they have the condemnation figures for any BMW engine or ZF transmission. From my understanding their figures are based off universal averages of samples they receive. Those averages could be lower or higher than what the manufacturer deems acceptable.

In addition due to the low frequency of ATF changes and the even lower frequency of a UOA being delivered technically there are not enough data points to determine a good plan of action however there is more evidence that a 70k change interval is more appropriate than a 30k interval. What is this evidence you say? ZF published a severe service schedule of 48k-70k miles. The 6HP has been used in millions of vehicles (BMW,Jag,Audi,Rover,Bentley,Hyundai) and theses units have not been deemed as weak or have there been statistically significant numbers of failures. The two UOA's show high wear but its a toss up. All of this beats the anecdotal feel good reasoning behind a 30k mile OCI.

On side note I'm doing a pan drop at 50k miles. I don't like the how BMW programmed the transmission to hold 3rd or 4th gear to promote faster warm up on cold starts. It also holds this gear in city driving (trying to sustain engine temps for emissions perhaps?) as well. I just don't like it. I don't mind spending the money to do it and I'll send off a sample to BS so they can add to their data base.

I don't mind spending the money to do it and I'll send off a sample to BS so they can add to their data base.

Thanks for the links. And thanks for planning to expand the knowledge base. When you do the tranny fluid change, are you going to do a flush to get all the fluid out? Or multiple fill/drain cycles? Or just ~1/2 the fluid that comes out when you drop the pan?